Method for burning liquids

ABSTRACT

Liquid fuels such as hydrocarbon fuels are burned in an upright cylindrical chamber by introducing the liquid in a continuous stream into a peripheral zone at the bottom of the chamber, and simultaneously introducing air in a direction downwardly inclined and inclined away from the center of the chamber so as to create a vortex motion of the air in the chamber thereby to atomize the fuel.

United States Patent [191 Rasconi Aug. 7, 1973 [54] METHOD FOR BURNINGLIQUIDS 2,175,866 10/1939 Arnold 431/173 Inventor: A e a d e Rasconi,Chem d la 3,200,870 8/1965 Hanley et a1 431/173 Fauvette 4b, 1012Lausanne, Switzerland Primary ExaminerEdward G. Favors [22] Filed: July21 1971 Att0rneyYoung & Thompson [21] Appl. No: 164,498

Related [1.8. Application Data [57] ABSTRACT [62] Division of 4 1969Liquid fuels such as hydrocarbon fuels are burned in an abandonedupright cylindrical chamber by introducing the liquid in a continuousstream into a peripheral zone at the bot- [52] US. Cl. 43 1/9, 43l1/l73tom of the chamber, and Simultaneously introducing air CL... in adirection downwardly inclined and inclined y [58] Field of Search431/173, 9 from the center of the chamber so as to create a vortexmotion of the air in the chamber thereby to atomize the [56] ReferencesCited I fuel UNITED STATES PATENTS 2,501,688 3/1950 Peeling 431/335 X 1Claim, 2 Drawing Figures METHOD FOR BURNING LIQUIDS This application isa division of copending application Ser. No. 875,631, filed Nov. 12,1969 and now abandoned.

BACKGROUND OF THE INVENTION With known methods of burning liquid fuelsin conventional burners to which the liquid fuel and the combustion airare fed, it is not possible to burn fuels of widely different natureand'quality (viscosity, calorific value), or fuels such as used oilscontaining, for instance, iron filings.

OBJECT OF THE INVENTION The purpose of the invention is to provide amethod enabling any kind of fuel to be used, and even allowing thesimultaneous use of several different fuels. The

method according to the invention comprises using a PREFERRED EMBODIMENTOF THE INVENTION The accompanying drawing illustrates, by way of anexample, an embodiment of the invention.

FIG. 1 is an axial section of this embodiment, and

FIG. 2 is a section along the line 2-2 in FIG. 1.

The illustrated method involved in the use of a stove which comprises avertical cylindricaibarrel 1 having a casing 2, made of metal or masonryfor instance, and an inner lining 3 of fire-brick. The upper part of thestove may be provided with a cap having an opening for the discharge ofthe combustion gases or with an explosion flap in case the stove is tobe connected to a boiler or to another device for the recovery of thecalorific energy. These components are not shown. 1

The'base of the stove comprises four nozzles 4 situated in the lowerpart of the stove and opening in the bottom of the latter whichconstitutes a combustion chamber 5. Each nozzle forms an angle with thecorresponding diameter of the stove, as shown in FIG. 2, and constitutesan air inlet oriented in such a manner as to produce a vortex motion ofthe air in the combustion chamber. The air thus introduced, owing to itsvortex motion and to its flow towards the upper part of the stove, takeson a helicoidal motion of reduced pitch. The air may be injected at avery high speed through the nozzles, for instance at a speed of from 80to 100 m/s, so that the vortex motion may be very fast and sweep thewhole surface of the combustion chamber. The angle of injection ischosen according to the dimensions and the operating characteristics ofthe stove. The latter may comprise means to adjust the direction of theincoming combustion air, i.e. the angle formed by each nozzle 4 with thecorresponding diameter of the stove.

In the illustrated embodiment, the nozzles constitute a single bank, butseveral banks of nozzles could be arranged over the height of thecombustion chamber or in the bottom of the stove.

The air is led to the nozzles 4 by a manifold 6. In the case where thereare several banks of nozzles, a single manifold may feed all thenozzles, or else each bank may have its own manifold. These may then beseparately fed or else-they may all be connected to a common manifold.

The stove comprises, placed above the nozzles 4 and the manifold 6, fournozzles 7 fed by a manifold 8, the air thus introduced into the stovebeing destined to adjust the temperature of the upper part of the stove.

The combustion air introduced through the nozzles 4 and the air foradjusting the temperature introduced through the nozzles 7 can befurnished by one or more blowers, having means for adjusting the airdelivery in the distributing manifold.

The stove comprises in its bottom ducts 9 constituting fuel inlets, theducts 9 opening into the combustion chamber 5 through ports 10 arrangedin the peripheric zone of the floor 11 of this chamber. The position ofthe ports 10 in relation to the nozzles 4 is such that the air jetformed by these nozzles instantaneously atomizes the fuel to fineparticles which ignite immediately and the combustion of which ispractically instantaneous. Owing to the helicoidal motion of thecombustion air, combustion can take place in a combustion chamber 5 ofreduced height, which may be of the order of the diameter. of the stove,for instance. The

combustion of the fuel introduced through the ducts 9 is started bymeans of a small auxiliary burner placed in one of the nozzles 4 (thisburner is not shown). This burner may be provided with a cell forchecking the flame.

To start the stove, when this stove is used for the combustion of a fuel(used oil, for instance) without using a boiler to recover calorificenergy, the auxiliary burner is first started, this auxiliary burnerburning oil fuel. After a time interval of the order of 15 to 30seconds, combustion air is injected through the nozzles 4 after checkingthe operation of the auxiliary burner. As soon as the air flows, fuel isinjected through the ducts 9. After a short lapse of time, of the orderof 15 seconds, the auxiliary burner is cut off and the stove goes onburning by itself. The normal rate of operation of the stove may beadjusted by governing the air/fuel ratio in such a manner as to give anexcess of air enabling peak conditions to be absorbed in case of a fuelhaving a nonuniform calorific value.

Several fuel inlets are provided, so as to inject simultaneously intothe combustion chamber several fuels having very differentcharacteristics, for instance fuels which do not mix well or not at alland having very different calorific values. The separate injection ofthe fuels enables a mixture, after atomization, to be obtained in thechamber having a practically constant calorific value.

The operation of the stove depends on several factors: the variablecalorific value of the fuel, minimum and maximum service temperature,etc. It is thus'necessary to be able to vary the different factors whichhave to be taken into account, such as the rate of delivery of the fuel,the rates of delivery of the combustion air and' the thermal regulationair, and this by manual or by au tomatically controlled means.

The minimum operating temperature is a function of the kind of fuel usedand must be sufficient to ensure complete combustion of the latter andto avoid smells.

This temperature is generally above 800 C. The maximum temperature is afunction of the quality of the fire bricksforrning the lining 3 and mustnot exceed the temperature which this lining is able to stand.

which is inclined away from the center of the chamber thereby to createa vortex motion of the air in the bottom of the chamber with the airentering the chamber at a speed sufficient to atomize the fuel in thechamber,

said speed being about to meters per second.

1. A method for burning liquid fuel in an upright cylindrical combustionchamber, comprising introducing a continuous stream of liquid fuel intoa peripheral zone of the bottom of the chamber, and simultaneouslyintroducing air separately from said fuel into the lower part of thechamber in the form of at least one stream which is inclined away fromthe center of the chamber thereby to create a vortex Motion of the airin the bottom of the chamber with the air entering the chamber at aspeed sufficient to atomize the fuel in the chamber, said speed beingabout 80 to 100 meters per second.